Question

Why do local variables lose their values between calls to the function in which they are defined?

Short answer

Answer: Local variables lose their values between calls to the function in which they are defined because they have a limited scope. They are created and initialized within the function when it is called, and destroyed when the function call is finished. This ensures that local variables are organized and only accessible within the specific function, which helps avoid naming conflicts and keeps the code clean.

Step-by-step solution

Understand Local Variables

Local variables are variables defined within a function. They have a limited scope, which means they can only be accessed and their value can be changed within the function where they are defined. When a function is called, the local variables are created and initialized, and when the function call is finished, the local variables are destroyed.

Scope of Local Variables

One key concept to understand about local variables is their scope. The scope of a variable determines the region of the code where a variable can be accessed. Local variables have a local scope, which means they can only be accessed within the function in which they are defined. This helps in avoiding naming conflicts and keeping variables organized within the functions.

Function Calls and Local Variables

When a function is called, the local variables are created and initialized within that function. As the function executes, the local variables are used and modified as needed. Once the function finishes executing and returns control to the calling code, the local variables are destroyed. Since local variables only exist within a specific function call, their values are not preserved between different calls to the function.

Example

Let's consider a simple example of a function that calculates the square of a number. ```python def square(number): result = number * number # result is a local variable return result ``` When we call the `square` function, the local variable `result` is created and initialized within the function call. After the function finishes its execution, `result` is destroyed, and its value is lost. If we call the `square` function again, a new `result` variable will be created, and the old value will not be preserved.

Conclusion

Local variables lose their values between calls to the function in which they are defined because they have a limited scope. They are created and initialized when the function is called, and they are destroyed when the function call is finished. This ensures that local variables are organized and only accessible within the specific function, which helps avoid naming conflicts and keeps the code clean.